Where there’s a will there’s a way: A longitudinal investigation of the interplay between recovery motivation and self-efficacy in predicting treatment outcome.

The psychological construct of self-efficacy plays a key role in both general, as well as addiction-specific, models of health behavior change and is well supported empirically. As a predictor of treatment outcome it has proven useful; however, to further clarify the nature and role of self-efficacy in predicting the complexities of addiction recovery, it would seem crucial also to consider an individuals' motivation to carry out that future behavior, because the degree to which a measure of self-efficacy predicts behavior may be contingent upon whether that individual is also motivated to enact it. To this end, we tested an interaction model of self-efficacy and motivation on treatment outcome. Young adults (N = 302; M = 20 years; 74% male) undergoing residential substance use disorder treatment were assessed at treatment intake, discharge, and 3, 6, and 12 months postdischarge on self-efficacy (SE), motivation for sobriety (MS), and percent days abstinent (PDA). Hierarchical linear modeling (HLM) results revealed main effects for abstinence SE and MS across time, but a significant interaction was detected, indicating that the influence of SE on PDA depended on MS. Further analysis revealed that for patients high in SE the level of MS made a small, but significant, difference on PDA, whereas for those low in SE, high MS made a substantial difference, such that their outcome was not different than patients with high SE. Findings highlight conceptual nuances in SE theory; and, clinically, convey optimism that, even if a patient reports low confidence in their ability to remain abstinent, it does not necessarily follow that they will have poor outcome, especially if they have a strong recovery motivation.